The spread of the species Orosanga japonica (Melichar) (Hemiptera: Ricaniidae), which was initially identified in our earlier study in pheromone traps in 2010, is studied along with its host plants and biology. The pest has been detected in six districts of Istanbul and on 22 different host plants. Of these hosts, 17 are new records for Turkey. The province of Istanbul constitutes the insects most westerly distribution in Turkey. In the study area, one generation per year have been recorded.